Optimizing Patient Analgesic Experience During IVF

Background:

A UK telephone survey (Bokhari, 1999) showed that during TUGOR, 48% of UK fertility centers were using conscious sedation, 29% general anaesthesia, 12% conscious sedation with regional anaesthesia (neuraxial block or PCB), and 2% regional anaesthesia alone. A review article (Blahos 2009) details the many different types of anaesthesia used during TUGOR. These may include combinations of the following: general anaesthesia, regional anaesthesia, local anaesthesia, conscious sedation, and alternative methods of anaesthesia (electro-acupuncture, patient controlled sedation). No recent studies were found detailing the frequency of each of the various anaesthetic options in use at fertility centers across North American.

A prospective, randomized, double-blind and placebo controlled study (Ng, 1999) showed that paracervical block combined with conscious sedation was superior to conscious sedation alone. This study used a combination of drugs (mepiridine and diazepam) not used at our center. The use of fentanyl and midazolam was first described by Harrison in 1992 for conscious sedation. In 2001 Sephton et al published a cross over audit of patient preferences comparing mepiridine, diazepam and promethazine to fentanyl and midazolam, showing superiority of fentanyl and midazolam. Midazolam has sedative and amnestic properties, whereas diazepam has no amnestic properties. The amnestic properties of midazolam make it a superior medication for overall patient experience during TUGOR, as they are less likely to recall potentially painful parts of their procedure. Midazolam has also been shown to act synergistically with fentanyl, thereby decreasing not only the actual pain recalled, but the actual pain experienced by patients. Since the only randomized control trial demonstrating the benefits of paracervical block was performed using mepiridine and diazepam, we intend to repeat the study using the superior combination of fentanyl and midazolam.

Study Rationale:

The oocyte retrieval may be the most painful part of fertility treatment. Our goal is to minimize patient discomfort and improve overall patient experience during fertility treatments. We do not know if PCB improves pain scores in the era of wider use of fentanyl and midazolam for sedation. Fertility centres may be subjecting their patients to a painful PCB injection without proven benefit. This study aims to assess whether a PCB in addition to conscious sedation can be abandoned without impacting the patient's overall pain experience.